Our goal is to make a direct connection between noradrenaline (NE) modulation in the main olfactory bulb (MOB), changes in MOB network output and behavior. We hypothesize that learning will induce, through NE, an overall increase in synchronization of mitral cell ensemble activity to the learned odor. We have preliminary evidence that complete blockade of NE signaling in the bulb impairs but does not impede an adult mouse's ability to discriminate between odor cues. We are currently characterizing the modulation occurring in olfactory bulb neuronal networks by recording from the mitral cell layer, the output neurons of the olfactory bulb, in awake-behaving mice engaged in an olfactory discrimination task. Finally, we will determine whether blockade of NE signaling will impair the changes in mitral cell activity observed during behavior.